Device and method for removing molten steel slag inclusion in continuous casting tundish

Abstract

The invention relates to a device and method for removing molten steel slag inclusion in a continuous casting tundish. The device comprises a turbulence controller, air curtain ventilation bricks, parapets and blocking dams, wherein the air curtain ventilation bricks (2) are located between the turbulence controller (1) and the parapet (3) and fixed to a tundish bottom permanent liner, the horizontal distance a between the longitudinal center line of the turbulence controller (1) and the longitudinal center line of the air curtain ventilation bricks (2) ranges from 400 mm to 600 mm, the horizontal distance b between the air curtain ventilation bricks (2) and the parapets (3) ranges from 200 mm to 700 mm, and the horizontal distance c between the parapets (3) and the blocking dams (4) ranges from 200 mm to 700 mm. By means of the method and device, the slag inclusion with the equivalent diameter larger than 50 microns in a continuous casting slab is basically removed, and the amount of micro slag inclusion with the equivalent diameter smaller than 50 microns in the continuous casting slab is reduced by more than 60 percent compared with the amount of the micro slag inclusion removed under the using condition that one tundish is internally provided with the turbulence controller, the parapets and the blocking dams and is reduced by more than 30 percent compared with the amount of the micro slag inclusion removed under the using condition that one tundish is internally provided with the turbulence controller and the air curtain ventilation bricks.

Description

technical field [0001] The invention relates to a device and method for removing liquid steel inclusions in a continuous casting tundish, belonging to the technical field of iron and steel metallurgy continuous casting tundish technology. Background technique [0002] In the tundish of the continuous casting machine, a flow control device composed of a turbulent flow controller, a retaining wall and a dam is installed, which can change the running route of the molten steel in the tundish, prolong the residence time of the molten steel in the tundish, and promote the floating and melting of inclusions. The metallurgical function of removing and reducing the inclusions inside the slab and changing the shape of the inclusions. In recent years, in order to meet the requirements for the control of inclusions in the development and production of high-purity clean steel, the technology of continuous casting tundish air curtain retaining wall has been studied and applied, that is, t...

AI Technical Summary

Problems solved by technology

[0005] In the actual production process, after long-term production practice, it has been proved that the existing flow control device and the continuous casting tundish air curtain retaining wall technology have technical defects: (1) the continuous casting machine tundish is set by The combination of turbulence controller, retaining wall and retaining dam can only effectively remove inclusions with equivalent diameter greater than 50 μm, but cannot effectively remove tiny inclusions with equivalent diameter less than 50 μm; in the tundish of continuous casting machine The technical scheme of setting air curtain permeable bricks inside can only effectively remove tiny inclusions with equivalent diameters less than 50 μm, but cannot effectively remove inclusions with equivalent diameters greater than 50 μm; (2) The installation positions of existing air curtain permeable bricks are: Technical defect: The existing air curtain permeable brick replaces the dam or is installed in the pouring area between the dam and the upper nozzle of the tundish, and the actual application effect of effectively removing tiny inclusions with an equivalent diameter of less than 50 μm is poor; (3) In order to remove The effect of inclusions in molten steel requires that the bubbles produced by air curtain bricks have a small diameter and high density, but the slit air curtain bricks produced by the existing technology have large pores, generally with an equivalent diameter greater than 50 μm, resulting in The equivalent diameter of the bubbles is relatively large (measured by the water model experiment, the equivalent diameter of the bubbles is greater than 1.5mm) and the number is small, and the density of the bubbles forming the air curtain retaining wall is small, so the actual application effect of removing inclusions is not ideal

However, this patent has the following disadvantages. Although the upper retaining wall and the lower retaining wall can remove a part of the inclusions with an equivalent diameter greater than 50 μm, the removal effect is not ideal, and the pores of the air curtain permeable brick are large, and the diameter of the argon bubbles produced is relatively large. Rare, the removal of inclusions with an equivalent diameter greater than 50 μm and inclusions with an equivalent diameter less than 50 μm is not ideal

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